DESCRIPTION (Applicant's abstract): Three recent developments have created a critical need and an opportunity to better understand medical decision making abilities in cognitively impaired elderly adults. First, the Patient Self-Determination Act has mandated patient participation in medical decisions. Second, the legal system has shifted the basis for determining competency to participate in medical decisions, now emphasizing specific decision-making capacities rather than general mental conditions. Third, new forensic assessment instruments have been released which aim to assess these decisional capacities. Yet legal standards are not scientifically grounded and instruments to measure these require additional validation. These developments have occurred in the context of a large and growing number of adults surviving into old age during which time they are at increasing risk for dementia and compromised decision-making capacities. The proposed research aims to provide an empirical basis for evaluating competency consent through investigation of four questions: 1) What is the construct validity of the four decisional capacities recognized in the law? 2) How do these decisional capacities relate to cognitive abilities? 3) Which of these decisional capacities are impaired in early dementia and to what extent? 4) What is the progression of decisional impairments over time? Results of the proposed research have potential implications in scientific, clinical, and legal settings. The results will link legal standards for competency to cognitive abilities, providing a more scientifically grounded model of decisional making in the context of competency; enhance the reliability and validity of assessments of patients' capacities to participate in medical decisions; and suggest ways in which clinical policy and legal standards could be changed to be more consistent with clinical science.